MEMPHIS — As the game began slipping away, his team unable to score consecutive baskets, stop Jerryd Bayless (who entered Saturday night averaging less than 8 points per game), or even execute a play without a pass bouncing off a leg, Doc Rivers began pestering the officials.

He already had picked up a technical foul, and was looking for the bigger prize, an ejection. So he berated official Zach Zarba about every call, and it seemed Zarba was on to Rivers’s strategy and ignored his pleas for admonishment.

As the game crept into the latter stages and the Celtics trailed by 20-something, Rivers inserted his reserves, most of whom had been with the team about three weeks, and began coaching as if it were his son Austin’s Pee-Wee team.

Rivers instructed. He clapped. He encouraged. He supported. That quintet began to generate points, defensive stops, and confidence. And their run became improbable, reaching 25-6 after two Jordan Crawford free throws in the final 19 seconds.

Unfortunately for the Celtics, Jason Terry missed the second of three free throws that would have cut the deficit to 1, and a short while later Rivers walked off the court a less frustrated man after the Celtics, without Kevin Garnett and Courtney Lee, lost, 110-106.

Both were out with left ankle sprains — Rivers didn’t find out about Garnett’s injury until late Friday night — so the coach went with a smallish lineup against one of the league’s bigger teams and the results were eventually disastrous. After a strong start (12-2), the Celtics allowed Memphis to shoot 55.8 percent in the first half and allowed Bayless to score 20 in 17 minutes.

It was to the point of embarrassment. Without Lee to defend, Rivers went with Crawford, and he was baked by Bayless’s stepback jumper. He tried Terry, who couldn’t chase Bayless around screens. And every time he attempted to summon Avery Bradley, Memphis coach Lionel Hollins inserted Mike Conley, preventing any Bradley-Bayless matchup.

The Grizzlies extended their lead to 17 in the third and 21 in the fourth (98-77) before Rivers nearly imploded. He then pulled Paul Pierce and the rest of the starters and went back to basics.

“I was trying to push our guys and I didn’t think we got some [calls],” Rivers said. “[In the fourth quarter], I thought the guys met my intensity. And that’s all I want every night. I want to win every night. We don’t go into games thinking, ‘We’ve got a lot of guys hurt and we can’t win.’ We go into games thinking, ‘We’ve got a lot of guys hurt and somebody else is going to help us win.’ That’s how we’ve got to be and everybody has to lead everybody.”

Pierce led the Celtics with 26 points and Crawford added 21 off the bench. Crawford had his fingerprints all over this strange game, drawing a technical from Bayless in the first half and then getting one in the fourth quarter for arguing a no-call on a goaltending.

The first half began so promising, with the Celtics playing with more energy than Friday. After Tony Allen scored the first basket for the Grizzlies, the Celtics countered with 12 consecutive points, including back-to-back buckets by Pierce.

But after playing scrappy on defense through the first few minutes, the Celtics began practicing those same habits that have allowed their last three opponents to feast on their pick-and-roll defense.

Pierce extended the lead to 27-21 with a 3-pointer at the 2:02 mark and that’s when the game changed as Hollins inserted Bayless and told the guard to shoot ­every time he was open.

The Celtics were helpless without Lee’s defense. Bayless scored Memphis’s last 8 points of the quarter to take the lead, only to have Pierce counter with two more hoops. While the Celtics held a 31-29 lead after the first quarter, there were discouraging signs littered all over FedEx Forum.

Bayless added 12 more points in the second quarter and the Grizzlies led by 10 at the break. The Celtics continuously allowed him to spring open off screens and the results were ghastly. But the late rally offered hope, but only if the Celtics are blessed with health.

“It was good for them to go out there and get their hands dirty,” Pierce said. “They fought hard. They didn’t look at the score, they just played as hard as they could for the minutes they got. That’s what coaches want to see.”